Collapsible table employing legs for supporting the table in extended and collapsed positions



Nov. 17, 1959 J UNDE COLLAPSIBLE TABLE EMPLOYING LEGS FOR SUPPORTING THE TABLE IN EXTENDED AND COLLAPSED POSITIONS Tiled Nov. 8, 1956 3 Sheets-Sheet 1 \.I. II 111 IN V EN TOR. LEONARD J. L/IVDE ATTORNEY Nov. 17!, 1959 L. J. LINDE ,913,294 COLLAPSIBLE TABLE EMPLOYING'LEGS FOR SUPPORTING THE TABLE IN EXTENDED AND COLLAPSED POSITIONS Filed Nov. 8, 1956 3 Sheets-Sheet 2 IN VEN TOR. LEONARD J. L M/DE ATTOR/VE Y,

N 1959 L. J. LINDE 2,913,294

COLLAPSIBLE TABLE EMPLOYING macs FOR SUPPORTING THE TABLE IN EXTENDED AND COLLAPSED POSITIONS Filed Nov. e, 1956 s Sheets-Sheet .3

IN V EN TOR. LEONARD J. LIA/DE ATTORNEY nite COLLAPSIBLE TABLE EMPLOYING LEGS FOR SUPPORTING THE TABLE 1N EXTENDED AND COLLAPSED POSITIONS This invention relates to folding or collapsible tables, and more particularly to relatively large collapsible tables for department store display areas, for playing table tennis or Ping-pong, or for the use of toy electric trains and the like requiring a sizeable play area.

It is common knowledge that department stores need extra table display areas at sale times or during seasonal buying rushes. Heretofore these tables required storage space when not in use and labor to bring them to and from storage when needed.

With the increased popularity of indoor games requiring a large play area, such as Ping-pong, or the all-year- 'around pleasure of playing with electric trains, it has become increasingly important and desirable to provide a large table which may be collapsed or folded up at will and readily rolled away for temporary storage. This type of table is particularly needed in our modern homes which utilize substantially all of the available space for every-day living. Heretofore, collapsible tables provided for this purpose lacked the rigidity required or were so bulky, cumbersome and heavy in weight that they could not be readily handled by a single individual.

Therefore, in accordance with the invention claimed a new and improved collapsible table is provided which may be collapsed or opened up to table extended position by a single individual. The table comprises a pedestal structure having a guiding means extending from the top toward the bottom thereof, and at least one table top panel. A protrusion is mounted on the panel for movement vertically along the guiding means of the pedestal structure. A spring biased latch means is disposed between the panel and the pedestal structure and is provided with a member for engaging and holding the protrusion. The protrusion when engaged by the latch means causes the panel to lie in a substantially horizontal position. A plurality of collapsible legs may be operably mounted on the underside of the panel for supporting the panel when in substantially a horizontal position. Means are provided for actuating the latch means against its spring biasing means to remove the member from engagement with the protrusion whereby the table is collapsed by causing the protrusion to travel along the guiding means in a predetermined direction. The panel and legs are rotated by the protrusion to substantially a vertical position adjacent the pedestal structure during movement of the protrusion in the predetermined direction along the guiding means.

It is, therefore, one object of the present invention to provide a new and improved collapsible table.

Another object of this invention is to provide a new and improved collapsible table which is sturdy, rugged, and durable when in table extended position and which may be readily and easily collapsed by one person.

A further object of this invention is to provide a new and improved collapsible table which may be collapsed from one side thereof by a single operator and then rolled away for storage.

A still further object of this invention is to provide a new and improved collapsible table wherein the ends of s, I tem fl ce the table panels are disposed upwardly during a table collapsing operation and thereby elevate the table upon a dolly mechanism forming a part of the table for readily rolling the table to a storage space.

A still further object of this invention is to provide a new and improved collapsible table for toy electric train use in which the table panels are disposed upwardly when the table is collapsed but spaced apart a predetermined distance to provide clearance for toy train equipment mounted on the table panels.

A still further object of the invention is to provide new and improved hardware for use in the construction of the collapsible table.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a collapsible Ping-pong table embodying my invention;

Fig. 2 is a side view of the table shown in Fig. 1 illustrating in dot dash lines the table in table open position and in full lines the table in table collapsed position;

Fig. 3 is an enlarged partial perspective view of one end of the table showing the position of the dolly and collapsible legs in table extended position;

Fig. 4 is an enlarged partial perspective view of the structure shown in Fig. 3 with the dolly and collapsible legs in table collapsed position;

Fig. 5 is an exploded perspective view of a modification of the hinge means and spring biased latch means illustrated in Figs. 1 to 4, inclusive;

Fig. 6 is a partial perspective view of a further modification of the hinge means and pedestal top structure illustrated in Figs. 1 to 5, inclusive;

Fig. 7 illustrates a side view of a modification of the hinge structure shown in Fig. 6;

Fig. 8 is a perspective view of an additional means for holding the panels illustrated in Figs. 1 to 7, inclusive, in co-planar alignment;

Fig. 9 is a side view of a modification of the collapsible table illustrated in Figs. 1 and 2 wherein the panels shown in dot dash lines in collapsed position are spaced apart a predetermined distance;

Fig. 10 is a side view of a modification of the collapsible tables illustrated in Figs. 1-9 wherein a single panel is pivotally mounted to lie parallel with a supporting wall or to extend out therefrom in table extended position;

Fig. 11 is a cross sectional view through the table structure shown in Fig. 10 taken along the line XX;

Fig. 12 is a perspective view of a further modification of the hinge and protrusion means illustrated in Figs. 1, 5, 6, and 7;

Fig. 13 is a modification of the dolly structure shown in Figs. 1 to 4, inclusive, and Fig. 9.

Fig. 14 is a perspective view of a further modification of the collapsible table illustrated in Figs. 1 to 13, inclusive;

Fig. 15 is a partial cross sectional view of the table collapsing means illustrated in Fig. 14; and

Fig. 16 is a perspective view of the clamping members illustrated in Fig. 14 for supporting the table legs in table extended position and for forcing a roller means into engagement with the fioor in table collapsed position.

Referring more particularly to the drawings by characters of reference, Figs. 1 and 2 illustrate a collapsible table 10 comprising two top panels or panel members 11 and 12 having joining edges 13 that are, supported by a pedestal structure including a wheeled base or dolly structure 14 and two upright support members 15. Panel members 11 and 12 are each supported between their ends by a pair of foldable or collapsible legs 16, each pair being secured together by cross members 17 and cross braces 3 18. The bottom ends of the legs 16 are hingedly attached to the pedestal structures rectangular base 19 one at each corner thereof and each hingedly attached at the other or top end thereof to the underside of one of the panel members 11 or 12.

Pivotally attached to the inside periphery of the rectangular base 19 near the center of its largest members are a pair of dolly members, each dolly member comprising a pair of arms 20 and 21 which are interconnected to gether at their free ends by a cross brace 22. One dolly member extends from substantially the center of base 19 in one direction and the other dolly member extends from substantially the center of base 19 in an opposite direction toward the other end of base 19. A caster 23 is provided on the underside or floor engaging side of the free end of each of arms 20 and 21 of the dolly members. As will be readily seen from Figs. 3 and 4, legs 16 are provided with cam surfaces 24 which upon collapse of panel members 11 and 12 engage the cross braces 22 of the dolly members to force the casters 23 of the dolly structure intoengagement with the floor thereby raising the pedestal structure a predetermined distance off of the floor. This action permits the collapsed or folded table to be readily moved inasmuch as the entire weight of the table is then supported by the casters.

In accordance with the invention claimed each of the upright support members 15 are provided with vertically extending slots 25 extending from the top or near the top of members 15 toward or to the bottom of members '15. These slots form a guiding means or track for the movement of a protrusion or extension arm 26 mounted near or forming a part of the hinge means 27 joining edges '13 of panel members 11 and 12 together. The protrusion or extension arm 26 of each hinge means as shown in Figs. 1 and 2 extends outward from hinge means 27 a distance sufiicient to lie within the slot in upright support members 15. Thus, when panel members 11 and 12 are collapsed or extended in horizontal table position the extension arms move down and up within slots 25 of support members 15.

As shown in Figs. and 6 the end of the extension arms 27 may be formed as a cylindrical rod or roller 28 or may be formed as a roller having acollar or flange 29 arranged around the outer periphery thereof. The flange 29 shown in Fig. 6 rides on the outside of the upright support members 15 and when extension arms with flanges 29 are used on both sides of panel members 11 and 12 they hold the upright support members 15 to the panel members forming a sturdy, unitary structure. If desired the extension arms 26 as shown in Fig. 7 may be provided with two flanges 29 and 3b. Flange 30 is formed to lie around the periphery of arm 26 a predetermined distance in from the end thereof so as to lie on the inside of the outline of slot 25.

A spring biasing latch means 32 is mounted on the pedestal structure and more particularly on the upright support members 15 for controlling the movement of the protrusion or extension arms 25 within the vertical slots 25. Latch means 32 is provided with a supporting top or surface 33 which holds in a given position the protrusion or extension arm 26 when it is in table open or extended position. Surface 33 may be at the top of latch means 32 or at any other place on its surface. By supporting the arms 26 the latch means 32 causes the panels to lie in substantially ,co-planar alignment. As shown in Figs. 1 and 2 the latch means is formed to fit within an indentation or enlargement 34 of slots 25 and to lie in co-planar alignment with the surface of upright support members 15. The latch means 32 is biased into slot 25 by a suitable spring 35 and the latch means reciprocal movement is controlled by a pin 36 which is either fastened to latch 32 or the wall of the enlargement 34 of slot 25. Either upright support member 15 or latch 32 is provided with an aperture for receiving pin 36 depending on whether member 15 or latch 32 supports pin 36. Figs. 1 to 4, inclusive, show latch means 32 as being mounted within the enlargement of slot 25 nevertheless it is within the scope of this invention, as shown in Fig. 5, to mount the latch means any place on the pedestal strucure which permits the desired movement of latch 32 to support and trip the collapsible panels 11 and 12. 1

In Fig. 5 the top of the upright support member 15 is provided with a pair of metallic puuchings 38 which support the movable trip latch 39. Latch 39 is pivotally mounted at 40 on the punohings 38 and biased by the expansion spring 41 to block slot 42 formed in each punching element. Slots 42 are vertically aligned with slots 25 formed in upright support members 15 to provide the path for movement of the protrusion or extension arms 26. As shown in Fig. 5 the spring biased latch means 3? is disposed between the pedestal structure comprising the upright members and the panel members. Although the latch means is shown pivotally mounted with its panel member supporting surface at its top it is within the scope of this invention to pivotally mount the latch near the top of punchings 38 with the latch extending downwardly therefrom and to provide a hook near the end of latch 39 to hold up or support the protrusion from above.

The spring biased latch means 32 is actuated against the action of its biasing means to trip the table 10 causing it to collapse by a cord or chain 43. As shown in Fig. 2 chain 43 may be fastened to latch means 32 and loosely held on the under side of the end of one of the panel members. If the table is in the table extended position and the operator pulls on cord 43 latch means 32 will be moved toward the operators end of the table and out of slot 25 thereby removing the support from under extension arms 26. Extension arm 26 in each slot 25 will drop therein toward the bottom thereof. By lifting manually upward on the outer end of the operators end of table 10 the inner edges 13 of panel members 11 and 12 will drop to the base of the pedestal structure. The extension arms 26 and edges 13 of panel members 11 and 12 in the collapsed position rest on a stifiening rail 44 of base 19 thereby saving edges 13 of panel members 11 and 12 from contacting with any parts that might batter itsshape. The entire table may be collapsed or extended to table open position by a single operator. Whenin collapsed position table 10 has its panel members slightly inclined toward each other to a statically balanced position. As described before, legs 16 are collapsed against the panel members when the table is in collapsed position as shown in Figs. '2 and 4.

To extend or open thetable the operator merely pulls down on the free end of either of panel members 11 or 12 and the panel members rotate to their horizontal positions causing extension arms 26 to move upward in slots .25 forcing latch means 32 and 39 in Figs. 1-4 and 6 and in Fig. 5, respectively, against their spring biasing means out of the path ofthemovementof extension arms 26 until extension arms 26 reach positions above latch means 32. At this pointthe spring biasing means of latch means 32 and 39 forces the latch means back under the extension arms to block their movement back toward the bottom of slots 25.

This action of the extension arms against the latch means isevident from the drawings. As shown in Fig. 8 stiffening bars 45 may be added, if so desired, one to each of the joining edges 13 of panel members 11 and 12 to help hold the panel members in co-planar alignment when in table extended position. Each bar extends under the adjoiningpanel to hold the adjoining panel in a horizontal position with the panel uponwhich the bar is afiixed.

When the collapsible table is used for Ping-pong the table structure may have incorporated on it a storage space for Ping-pong balls as well as Ping-pong paddles. The net construction comprising the net 46 and holding bars. 1 is so a n with. ns ct to th slda tabl tha it may remain permanently in place even though the table is fully folded. However, the net and holding bars may be readily detached from the table when the table is to be used for purposes other than Ping-pong. From Figs. 1 and 6 it will be noted that the holding bars 47 are formed to have a vertical portion 48 and a horizontal portion 49 extending at substantially a right angle to portion 48. Portion 49 is inserted into an opening 51 in the upright support members 15 or into aperture 52 formed in the metallic punching 38 forming the top of upright support members 15. The long vertical portion 48 and the top of upright support members 15 may be located a standard distance away from the sides of the table in accordance with the rules of the United States Table Tennis Association, if so desired.

It will be noted from Fig. 2 that when the two panel members 11 and 12 are folded against each other there is a space provided above the pedestal structure for the net structure. This is due to the fact that the panel members meet at a point substantially above the top of net 46. Accordingly, therefore, when the table is in a completely folded position the net is not touched or otherwise interfered with, and accordingly may remain attached to the table even though the entire table is completely folded.

Fig. 9 illustrates a further modification of the table structure shown in Figs. 1 to 8, inclusive, wherein an oflF-set hinge structure 53 is provided. Hinge structure 53 comprises an extension arm on protrusion 54 forming the pivot point of a pair ofright angle hinge arms 55. Hinge arms 55 may have a right angle surface member 60 attached to the ends of arms 55 to stiffen; the hinge structure. The horizontal portion of arms 55 as shown in full lines in the table extended or horizontal position is attached to the under side of panel members 11 and 12. Thus, when the panel members 11 and 12 are rotated to the table collapsed position as shown in dot dash lines in the manner heretofore described the panels will remain a predetermined distance apart. This distance apart is determined by length of portion 56 of arms 55 of the hinge structure 53. Fingers or support means 57 may be mounted at the ends of panel members 11 and 12, if so desired, to further support the panel members when in table collapsed position. If desired, a pair of swingably mounted legs 61 may be arranged at the two outer corners of the panel members 11 and 12. These optional legs 61 have the conventional break-braces 62 whereby the legs 61 may be disposed in upright position as shown in Fig. 9 or folded against the panel members in table collapsed position.

Fig. 10 illustrates a further modification of the present invention wherein a single panel member 12 and its col lapsible legs 16 are pivotally mounted on a pedestal structure 63 in the same manner as disclosed in Figs. l-4. Pedestal structure 63 is secured to a retaining wall 64 for supporting the table in collapsed as well as table extended position. Structure 63 may comprise one or more upright support members 65 each provided with a vertically extending slot 66 extending from the top toward the bottom of member 65 and defining an indentation 67. As is readily apparent panel 12 may be supported by two spaced apart upright members or one upright member arranged in the center of the panel member. The slot 66 formed in upright member 65 forms a guiding means for a protrusion 68 mounted on the edge 13 of panel member 12.

As shown inFi-gs. l and 11 latch means 69 comprises a right angle member 70 which may be biased if so desired by a spring 72 against the wall side of slot 66. One end of latch means 69 is pivotally mounted on panel 12 or, if so desired, loosely mounted on the shaft forming a part of protrusion 68. The free or other end of latch means 69 forms a supporting surface which engages the indentation 67 of slot 66 and holds protrusion 68 and panel 12 in table open or horizontal position. An operator by grasping the end of the right angle member 76 may quickly collapse the table by rotating the latch means out of indentation 67 to remove the support from under protrusion 68 and panel 12. Protrusion 68 then drops into slot 66 in the same manner as heretofore described to collapse the table. The table is extended to open position in the same manner as heretofore described for the other figures of the drawings. The structure shown in Figs. 10 and 11 may be used anywhere, such as department stores, homes, schools and places of business where a table is needed at a certain place periodically. By collapsing the table against the wall it is readily stored and out of the way without moving costs.

Fig. 12 illustrates a hinge means 73 and the extension arm or protrusion 68 wherein the protrusion 68 is separate from the hinge means. As shown the protrusion is mounted on the lower face of one of the panel members and arranged to extend within the slot formed in one of the upright members of'the pedestal structure.

Fig. 13 illustrates a modification of the dolly structure shown in Figs. 1 to 4 inclusive, and Fig. 9 wherein the cross braces 22 and casters 23 are mounted between legs 16 and on the lower sides or edge surfaces of thecam surfaces 24. Upon collapse of panel members 11 and 12 the dolly structure formed in this modification by braces 22 and casters 23 are forced into engagement with the floor thereby raising the pedestal structure a predetermined distance ofi of the floor. This action permits the collapsed or folded table to be readily rolled away. As is readily noted from Figs. 3 and 4 cross braces 22 and casters 23 may be used between each pair of legs 16 to make the table completely mobile.

Fig. 14 illustrates a further modification of the table structure shown in Figs. l to 13, inclusive, wherein the pedestal structure comprises a pair of inverted U-shaped tubular members 80 each having a bight 81 and a. pair of leg members 82 and 83. Leg members 82 and 83 are suitably secured at their free ends to a tubular base 84.

Base 84 comprises two pair of tubular members 85 and 86 which are telescoped together and held firmly in a substantially rectangular form by four clamping members 87.

Each U-shaped tubular member 80 is provided with a guiding means such as 'guide tube 88 which is suitably secured at one end to the bight 81 of member 80 and at the other end to base member 86 as shown in Fig. 14. Each guide tube 88 forms a track for the movement axially along its length of a sleeve or traveler 89 forming a part of a table collapsing means 90; Means 90 as shown in Fig. 15 further comprises a lever arm 91 which is pivotally mounted on one of the panel members 11 or 12. As shown in Fig. 15 lever arm 91 is pivotally mounted on the hinge bolt 92 of hinge means 93. Although if a table using only one collapsible panel is used such as the structure shown in Fig. 10 lever arm 91 could be pivotally mounted at any suitable place on either panel member 11 or 12 which provides the table collapsible action desired. Lever arm 91 is firmly fixed on one side thereof to traveler 89 for movement therewith and is provided with a pair of ears on the other side for supporting a pivotally mounted spring biased latch arm 94. Latch arm 94 is provided with a nose 95 at one end which is biased into an aperture 96 in guide tube 88 by a spring 97 when the table is in table extended position and a connection member 99 at the other end. Thus, when the table is in the extended or open position the guide tube holds the adjacent edges of the panel members in a horizontal position. To collapse the table thelatch arms 94 are moved against their spring biasing means to move noses 95 out of their apertures 96 in guide tubes 88. This action may be accomplished in any suitable manner such as by means of a handle 164 and a mechanical linkage connection including a tie rod 98'connecting member 99 of one end of one latcharm 94 together with the nose end of the other latcharm 94 (as shown in Fig. 14). By pushing on handle 104 the table is collapsed by forcing the lever arms against their spring biasing means to move noses 95 out of their apertures 96.

As shownin Fig. 16 the lower ends of each of the tubular legs 100 are provided with a strap 101 which is wrapped around legs 100 and suitably .secured thereto. The straps 101 are each provided with apertured ears 102 which form the loose pivotal mounting for legs 100 when they are mountedon base members 85 as shown in Fig. 14. .Casters 103 are secured to the lower ends of legs 100 in the usual manner and support the table structure when in the collapsed position in the same manner as described heretofore.

Although the structures are shown as metallic tubular members any suitable tubular members whether hollow or solid may be used.

Although but a few embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the .art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

;It is claimed and desired to secure by Letters Patent:

1. A collapsible table comprising a pedestal structure having a vertically extending guiding means, two table top panels, hinge means connecting adjacent edges of said panels together to form a fiat surface, a ring-shaped protrusion mounted on one of said panels for surrounding and moving vertically along said guiding means, spring biased :latch means disposed between said pedestal struc 'ture and said panels and provided with a member for :holding said protrusion in a given position on said guiding means, said protrusion when held by said latch means .ca'using said panels to lie in substantially co-planar alignment, a plurality. of collapsible legs each operably mounted at one end to the underside of said panels for supporting said panels when in substantially co-planar alignment and for elevating said .pedestal structure off of the floor when in the collapsed position, a triggering means mountedon the underside .of saidpanels for actuating said latch means when holding said protrusion in said given position against its spring biasing means to release said member from holding said protrusion whereby the table is collapsed by causing said protrusion to movealongsaid guiding means to the lower end thereof, said panels and said legs being rotated by said protrusion to substantially a vertical position adjacent said pedestal structure during movement of said protrusion toward the lower end of said guiding means.

i 2. A collapsible tablecomprising a pedestal having a vertically extending guiding means, two table top panels, hinge meansconnecting adjacent edges of said panels together to form a flat surface, a protrusion mounted on one of said panels for movement vertically along said guiding means, spring biased latch means disposed between said pedestal and said panels and provided with a member for holding said protrusion in a given position on said guiding means, said protrusion when held by said latch means causing said panels to be in substantially co-planar alignment, a plurality of collapsible legs each operably mounted at one end thereof to the underside of said panels for supporting said panels when in substantially co-planar alignment, pedestal elevating means associated with the other end of each of-said legs, triggering means mounted on the underside of said panels for actuating said latch means when holding said protrusion in said given position against its spring biasing means to release said member from holding said protrusion where- -by the table is collapsed by causing said protrusion to move along said guiding means to the lower end thereof, said panels and said legs being rotated by said protrusion to substantially a vertical position adjacent said pedestal during movement of said protrusion toward the lower end of said guiding means, said pedestal elevating means at said other end of said legs engaging with the floor and raising said pedestal off of the floor a predetermined distance.

3. A collapsible table comprising a pedestal having ,a vertically extending guiding means, two table top panels, hinge means connecting adjacent edges of said panels together to form a flat surface, aprotrusion mounted on one of said panels for movement .yertically along said guiding means, spring biased latch means disposed between said pedmtal and said panels and provided with a member for holding said protrusion in a given position on said guiding means, said protrusion when held by said latch means causing said panels to be in substantially coplanar alignment, a plurality of collapsible legs each operably mounted at one end thereof to the underside of said panels for supporting said panels when in substantially co-planar alignment, roller means associated with the other end of each of said legs, triggering means mounted on the underside of said panels for actuating said latch means when holding said protrusion in said given position against its spring biasing means to release said member from holding said protrusion whereby the table is collapsed by causing .said protrusion to move along said guiding means to the lower .end thereof, said panels and said legs being rotated .by said protrusion to substantially a vertical position adjacent said pedestal during movement of said protrusion toward the lower end of said guiding means, said rollermeans at said other end of said legs engaging with the floor and raising said pedestal off of the fioor a predetermined distance thereby permitting the table to be conveniently rolled away for storage.

4. A collapsible table comprising a pedestal structure having a vertically extending guiding means, two table top panels, hinge means connecting adjacent edges of said panels together to form a flatsurface, a ring shaped protrusion mounted on one of said panels for surrounding and moving vertically along said guiding means, spring biased latch means disposed between said pedestal structure and said panels and provided with a member for holding said protrusion in a given position on said guiding means, said protrusion when held by said latch means causing said panels to lie in substantially co-planar alignment, a plurality of collapsible-legs each operably mounted at one end to the underside of said panels for supporting said panels when in substantially co-planar alignment and for elevating said pedestal structure oif of the floor when in the collapsed position, roller means associated with the other end of each of said legs, means for actuating said latch means when holding said protrusion in said given position against its spring biasing means to release said member from holding said protrustion whereby the table is collapsed by causing said protrusion to move along said guiding means tov the lower end thereof, said panels and said legs being rotated by said protrusion to substantially a vertical position adjacent said pedestal structure during movement of said protrusion toward the lower end of said guiding means, said roller means at said other end of said legs engaging with the floor and raising said pedestal structure oil of the floor a predetermined distance thereby permitting the table to be con veniently rolled away for storage.

References Cited in the file of this patent UNITED STATES PATENTS 570,509 Selders Nov. 3, 1896 2,158,950 Swett May 16, 1939 2,204,107 Swett June 11, 1940 2,545,064 Alch Mar. 13, 1951 2,569,007 Klyce Sept. 25, i 2,645,539 Thompson July 14, 1953 2,764,460 Nelson Sept. 25, 1956 2,772,935 Read Dec. 4, 1956 2,792,270 Anderson May 14, 1957 

